package org.apache.commons.graph.builder

import org.apache.commons.graph.MutableGraph

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

/**
 * TODO Fillme!!!
 *
 * @param <V> the Graph vertices type
 * @param <E> the Graph edges type
</E></V> */
interface HeadVertexConnector<V, E> {
    /**
     * Specifies the head vertex for the edge
     *
     * @param <H> the Graph vertex type
     * @param head the head vertex
     * @return [TailVertexConnector] builded from the head
    </H> */
    infix fun <H : V> from(head: H): TailVertexConnector<V, E>
}

internal class DefaultHeadVertexConnector<V, E>(
    private val graph: MutableGraph<V, E>,
    private val edge: E
) : HeadVertexConnector<V, E> {
    override fun <H : V> from(head: H): TailVertexConnector<V, E> {
        //var head = head
        //head = Assertions.checkNotNull(head, "Null head vertex not admitted")
        return DefaultTailVertexConnector(graph, edge, head)
    }
}